Nope, D800 is for me and I may keep my D700 as a backup. I do not see anything for me in a lesser FF.
The majority of a FF system cost is the glass, filters, batteries, memory cards, softwares etc. When considering the full costs, the incremental between a D600 and say a D800 would be fairly marginal, perhaps counting for less than 10% of the total. I think one would need to base his selection on other factors that is more suitable for his/her need, say body or file weight, ISO, FPS etc.
If one is so tight on money, perhaps walking the FF path and its higher requirements is not that good of an idea but this question is so personal. Choosing a D600 for whatever reason is not an invalid choice and neither is choosing a D7000 or a D4/D800.
I find the thread title a bit troublesome as it seem to say 'comfort me in my D600 choosing by telling me why a D800 is a bad idea', pretty much in line with the numerous complains about the file size and the presumed bad ISO, but I can be wrong.